Preheat oven to 180°C and line a large tray with baking paper.
Place 160g toasted nuts and sugar into TM bowl and mill 8 sec/speed 8.
Add butter, salt, baking powder and soda, vanilla and flour.
Mix 6 sec/speed 6 until you have a breadcrumb texture.
Add soda water and knead 12 sec/Interval.
Add remaining nuts and chocolate and mix 6 sec/speed 6.
Spread the mixture into a large round on prepared tray and push into an even sided circle using your spatula. Cut across the circle to score into large wedges.
Bake 30 minutes or until golden around the outside.
Break apart and serve with butter, Nutella, or maple syrup.